If the sum of a number and 8 is doubled the result is 2 less

If the sum of a number and 8 is doubled, the result is 2 less than the number. Find the number.

Solution

Let the required number be x. Then the sum of a number and 8 is x+8 and2 less than the number is x-2 so that 2(x+8) = x-2 or, 2x+16 = x-2 or, 2x-x = -16-2 or, x = -18.

On verifying the result, 2(-18+8) = 2(-10) = -20 and -18-2 = -20.

Thus, the answer is -18.